3
Every 70 seconds the unit alternates between being a supply fan and an extract fan.
During the extract mode the units high efficiency heat exchanger collects and retains
heat from the extracted air, it then transfers the majority of this heat to the incoming air
during supply mode, recovering most of thermal energy which would be otherwise lost
in the ventilation process.
The unit can be run continuously at a set speed by adding an internal link, or controlled
via the dedicated controller, 149-SEN-CTRLS which allows speed selection and triggering
of free cooling mode.
S3 switch activates the “Free cooling “ (Bypass) mode , which stops alternate flow and
keeps the fan in “extract-only” or “intake-only” mode, to avoid the heat exchange when
necessary. To set the extract-only” mode or “intake-only”, place the integral jumpers as
per Fig. 20A or Fig. 20B).The front cover LED indicates when the Free cooling mode is on.
An automatic “Boost”mode can be achieved through a dedicated switch or room sensors
like 149-SEN-HY, 149-SEN-PIR or 149-SEN-CO2.
Wiring configurations:
1. Constant run with alternate flow and heat retention on Speed 1 only (Fig. 18A).
2. Constant run with alternate flow and heat retention on Speed 2 only (Fig. 18B).
3. Constant run with alternate flow and heat retention on Speed 3 only (Fig. 18C).
4. Constant run with alternate flow and heat retention on Speed 1 with boost to Speed 3
triggered by external switching device (ordered separately if required) (Fig. 18D).
5. Constant run with alternate flow and heat retention on Speed 2 with boost to Speed 3
triggered by external switching device (ordered separately if required) (Fig. 18E).
6. Operation using controller 149-SEN-CTRLS (ordered separately if required) (Fig. 18F).
(a) Off.
(b) Constant run with alternate flow and heat retention on Speed 1.
(c) Constant run with alternate flow and heat retention on Speed 2.
(c) Constant run with alternate flow and heat retention on Speed 3.
(d) Constant run on selected speed in extract or supply mode only (supply or extract
selectable at installation stage).
Please note that this switch can control one or two units to work in harmony i.e. when
one unit is extracting the other is supplying which can improve further the ventilation in
a room or home. Wiring diagram for 2 units, Fig. 18G.
“S1”
“S2”
Operation
O
O
OFF
I
O
Speed 1
O
II
Speed 2
I
II
Speed 3
S1 S2 S3
II
I
“S3”
Operation
Heat recovery
(Alternate flow)
Free cooling
OPERATION
WARNING: Ensure that the electric wiring to L and N is done correctly; an
incorrect connection will lead to malfunction or permanent damage of the fan.
Two or more units can operate at a fixed speed in a synchronised way (one unit extracts,
the other supplies, and viceversa). Wiring diagrams: Fig. 18A-18B-18C.
The initial starting air direction is achieved by setting the dedicated jumper (Fig. 20A-20B).
RESET OF THE SYNCHRONISATION
OPTION 1:
If two or more units are connected under the same main switch or under a
dedicated switch, to reset the synchronisation, the switch must be switched first OFF and
then ON to reactivate (Fig. 31).
SYNCHRONISATION IN CASE OF INSTALLATION WITHOUT CONTROLLER
